Fluids and solids obey different physical laws and, therefore, present different characteristics during the passage of these substances through small tubes moved by pressure differences, a physical phenomenon that governs the basic principle of vitrectomy. The removal of vitreous gel by cutting and aspiration, vitrectomy, is the main way to remove the vitreous. The fluidic aspects depend on aspiration and cutting rate, the propulsive mechanism of the aspiration system, the guillotine movement of the cutter, and the diameter and dimensions of the cutter probes and physical characteristics of the substance removed (solid or fluid). The input of fluids (inflow) must be equal to the output (outflow) to maintain this stability in the vitreous cavity. Inflow is provided by an irrigation solution infused into the eye to maintain the physiological shape of the globe and intraocular pressure. The outflow occurs through a variety of mechanisms and can be accomplished in different ways from a physical point of view. The outflow depends on probe size and caliber, port size, cut rate, and duty cycle. Pumps in vitrectomy machine are directly related to outflow. Three types of pumps are available, peristaltic, venturi, and valve timing. The valve timing pump marked a turning point for the transition from analog technology in Venturi and peristaltic pumps to the beginning of a digital era. In the future, cutting speeds will likely exceed 100–200 thousand cuts per minute, ensuring complete safety in vitreous removal and ultrasound is also very promising.